Apparatus for curling sheet metal



Aug. 22, 1967 E. R. BODNAR APPARATUS FOR CURLING SHEET METAL 2 Sheets-Sheet 1 Filed Jan. 1 5, 1964 FIG! Inventor ERNEST R. BODNAR Aug. 22, 1967 E. R. BODNAR 3,336,777

APPARATUS FOR CURLING SHEET METAL Filed Jan. 13, 1964 2 Sheets-Sheet 2 63 n 62 is? 68 Inventor ERNEST R. BODNAR United States Patent,

3,336,777 APPARATUS FOR CURLING SHEET METAL Ernest Robert Bodnar, 16 Easson Ave., Toronto, Ontario, Canada Filed Jan. 13, 1964, Ser. No. 337,464 11 Claims. (Cl. 72-146) This invention relates to a curling device for curling waste stock during high speed slitting operations as are normally carried on in metal processing mills and the like.

During certain types of metal slitting operations where comparatively large coils of metal are uncoiled and slit into smaller widths, the first portion of the roll which passes through the slitting machine is generally discarded as a starting end. Normally the starting ends are allowed to drop onto the floor at the output end of the slitter, whereafter the ends are chopped into suitable size for handling. It will be appreciated that the chopping operation is time consuming and, also, it adds to the overall cost of the slitting operation. In addition, the discard ends, normally attaining lengths of several feet, constitute a hazard due to sharp ends projecting upwardly from the slightly coiled strips. There is even a further hazard involved in workmen lifting such pieces since they are often quite heavy and have extremely sharp edges.

The present invention seeks to overcome these disadvantages by providing a curling unit which receives the discard ends and curls them into a compact coil, whereafter they may be dumped into waste bins or conveniently carried by material handling equipment such as for example fork trucks.

In addition to the problem of handling discard ends there is the further requirement for maintaining tension on the sheet of metal throughout the entire operation of uncoiling, slitting and recoiling. For this reason it is ad-v vantageous to provide some means near the end of the slitting line which will tension the strips of metal and thus provide a tension throughout substantially the whole length of the slitting line. In some instances it is feasible to provide a motor and brake device on the recoiling unit, whereby tension may be maintained on the metal strips at all times. Such a device has been disclosed in Canadian Patent No. 651,428 dated Oct. 30, 1962, entitled Strip Coiling and Re-coiling Apparatus.

However, in the case of a high speed slitting line the use of the motor and brake device is impractical as a tensioning means for the slitting line since, due to the high speed operation, the energy dissipation at the brake would be prohibitive. For this reason, resort is had to the method of the present invention which provides a DC drive coupled to a pair of pressure shafts and a voltage controller for the motor to provide a variable speed unit.

- Other objects and features of the invention will become apparent from the following detailed description and accompanying drawings in which like numerals refer to like parts.

' In the drawings:

FIGURE 1 is a side elevation of a presently preferred embodiment of this invention;

FIGURE 2 is a plan view of the curling device;

FIGURE 3 is a section along the line 33 in FIG- URE 1;

FIGURE 4 is a side elevation of a presently preferred embodiment of the invention as installed in a metal slitting line and shows the device, whereby the normal slitting and re-coiling operations are being carried on. Referring to FIGURE 1, FIGURE 2 and FIGURE 3,

the curling unit, indicated generally as 11, comprises a base 12 of hollow configuration and adapted to conceal and support the various piping and electrical services required for the operation of the unit 11. Base 12 is provided with a pair of shaft supports 13 and 14 located on top of base 12 and defining the input end of the curling unit 11. Supports 13 and 14 are adapted to receive a driven pressure shaft 15 rotatably therein, an adjustable pressure shaft 16 rotatably therein, adjustable shaft 16 being vertically movable from an engaged position adjacent shaft 15 to an at rest position substantially above and away from shaft 15 by means of a pair of hydraulic cylinders 17 and 18.

Shaft 15 is driven through a flexible coupling 19 and a speed reducer 20 by means of a DC motor 21, whereby a selected speed range for rotation of shaft 15 may be obtained. It is also preferable to provide both shafts 15 and 16 with self aligning type bearings whereby slight misalignment between both shafts during feeding of the discard ends therethrough may be tolerated without damage to the device.

A curling shaft 22 is rotatably supported on supports 13 and 14 in a position parallel to and spaced apart from pressure shafts 15 and 16. In this embodiment it is preferable to divide curling shaft 22 into sections whereby a mid support bearing 23 aids in maintaining the stiffness of shaft 22. Since it is desirable to curl the discard ends into a compact coil, then a comparatively small diameter curling shaft is used. Also, since it is desirable to extend the capacity, that is to say the width of the unit 11, then a comparatively long curling shaft is also desirable, and for these reasons the shaft 22 has been divided as shown. It will be further understood that curling shaft 22 may also be divided into further sections, or, alternatively, provided in one piece under certain circumstances, the

two piece shaft shown in the drawings being a preferred embodiment only. Curling shaft 22 rotatably supported by outer bearings 24 and 25 as well as centre bearing 23, is driven through flexible coupling 26 and speed reducer 27 by means of an AC motor 28.

A first diverting shaft 29 is rotatably supported in a pair of bearings 30 and 31. Shaft 29 is movable in the vertical direction from an operative position towards curling shaft 22 to an inoperative position away from shaft 22 in much the same manner that pressure shaft 16 is moved.

A guide table 32 extends the length of curling shaft 22 and is in a position between shaft 22 and pressure shaft 15 whereby the upper surface of table 32 is substantially tangent to shaft 22 and shaft 16, and thus forms a guide for material passing between shafts 15 and 16 toward shaft 22. In the operative position diverting shaft 29 is adjacent to the upper surface of table 32 thereby to guide the discard ends thereover.

A second diverting shaft 33 is rotatably supported and vertically movable on supports 13 and 14 in a manner similar to first diverting shaft 29, diverting shaft 33 being movable from an operative position adjacent to curling shaft 22 to an inoperative position substantially away from shaft 22. All three shafts 16, 29 and 33 being adapted for movement into and out of operative positions, are done so by means of hydraulic cylinders such as cylinders 34 and 35 for shaft 29, cylinders 36 and 37 for shaft 33, operating through sliding bearings supported by supports 13 and 14. In this preferred embodiment the cylinders are hydraulically operated which gives a somewhat resilient biasing of the rollers against the discard ends passing through the device which allows for slight variations in material thickness, thus assuring sufficient pressure being applied to discard ends to ensure proper curling thereof.

A catch bin, indicated generally as 38, is provided subjacent to curling shaft 22 and comprises a back wall 39 being curved and extending downwardly from support with table 32. A tilt arm 40 has a concave configuration and is movable from a support position as shown in solid line in FIGURE 3 to a dump or discharge position, as shown in phantom line in FIGURE 3, by means of an air cylinder 42. Cylinder 42 is pin jointed to the base 12 by means of a pin 43 and to tilt arm 40 by pin 44, whereby upon retraction of cylinder 42, arm 40 pivots about the pin 41 to assume the dump position.

As will be seen from FIGURE 3, curling shaft 22 is located somewhat below pressure shaft 15 whereby the table 32 is slanted downwardly from shaft 15 to shaft 22. Also, it will be seen that the diverting shaft 29, located substantially midway between shaft 22 and shaft 15, forces material passing shafts 15 and 16 slightly downwardly towards the curling shaft 22. Diverting shaft 33 is located in the in use, position, slightly above or even approximately level with the curling shaft 22, whereby the discard ends are diverted about curling shaft 22 by means of the curling shaft 22 being rotated by motor 28 as aforesaid.

In use, discard ends 45 coming from the slitting device (not shown), are passed between pressure shafts 15 and 16, shaft 15 thereby driving ends 45 therebetween. Pressure is provided on ends 45 by means of hydraulic cylinders 17 and 18, whereby sufiicient friction is provided to ensure continuous feed of the discard ends 45. Ends 45 passing from shafts 15 and 16 are diverted by diverting shaft 29, pressurably against table 32 and are diverted towards the curling shaft 22. Diverting shaft 33 forces ends 45 against the curling shaft 22 whereby the combined action of curling shaft 22 frictionally driving ends 45 and diverting shafts 29 and 33 maintaining the curvature of the ends 45, said ends are caused to assume a tight coil formation 46 as shown in FIGURE 3. This curling is continued until all of the discard ends 45 have passed through the device and over the curling shaft 22, whereafter coil 45 drops onto tilt arm 40 to be supported thereby. Upon the ends 45 being completely curled, cylinder 42 is retracted and tilt arm 40 pivots about pin 41 to dump or discharge coil 46 into a waiting waste bin, thereafter to be handled in known manner. Also, it will be seen that the back wall 39 is provided with a concave roof 47 which is substantially above the lower radius of curling shaft 22, whereby coil 46 will have room to coil without being strained into uncoiling as would otherwise be the case if a flat roof were provided. Thus the clearance back of curling shaft 22 is advantageous in providing a tight coil 46, and thus a compacted bundle of the discard ends 45.

In order to sever the discard ends 45 a slitting unit indicated generally as 48 in FIGURE 3 is provided having a motor driven knife 49 supplied by electric cable 50, mounted by means of rollers 51 onto a rail 52. Rail 52 extends the full width of the throat of the machine and is supported substantially in line with the contact line of shafts 15 and 16 by means of a support bar 53. Motor driven knife 49 may be any conventional type of power shear such as are available from manufacturers of this type of shearing equipment. In use the powered knife is forced against the edge of the material 45 by manual means, this being sufficient to sever the material.

It is preferable to provide a scraping knife or bar 54 (FIG. 3) pivotally supported on a shaft 55 whereby the bar 54 can be brought into contact with the shaft 15. A spring 56 is provided with an adjustment 57 whereby the blade 54 can be resiliently biased against the shaft 15. In this manner, particles of dirt and the like tending to collect on the shaft 15 from the material 45 passing thereon may be scraped off. If desired a second scraping bar or blade may also be provided on the pressure shaft 16.

A stop 58 is threadably secured in a bracket 59 and is provided with a lock nut 60 thereon whereby the position thereof may be varied as required. A pair of such stop assemblies are provided at each side of the machine immediately below the support for the diverting shaft 33, whereby the resting position of shaft 33 adjacent to the curling shaft 22 may be pre-set, thereby to control the radius of curvature of the coil 46.

Referring to FIGURE 4 a typical high speed metal slitting line is shown diagrammatically and comprises an uncoiling unit 61 feeding strip or sheet material over a guide roller 62 into a slitting device 63. The apparatus for maintaining tension in the shearing line and for curling waste ends, such as has been disclosed, is shown as 11 in the figure. In this view also, a scrap bin 65 is shown containing a curl of waste material 66 which has been dumped from the tilt arm 40 as previously disclosed. The slit material 67 is shown passing from the unit 11 into the recoiler 68.

During this portion of the operation, that is while the slit material is being recoiled, the pressure shafts 15 and 16 are maintaining tension on the material 67 coming from the slitting device 63 at all times. Thus, any tendency for speed-up in the slitting line can be accommodated by suitably varying voltage to the DC motor 21, an increase in supply voltage resulting in an increase of the speed of shafts 15 and 16. It will be understood that means for varying the voltage supply to the moter 21 is to be carried out in a well known manner by providing suitable electrical equipment available from manufacturers of such devices.

It will be further understood that during the slitting operation and the drive of the shafts 15 and 16 there is a constant tendency for over drive, whereby the shafts 15 and 16 actually slip on the material 45, the pressure of the cylinders 17 and 18 maintaining frictional contact of the shafts 15 and 16 on the material 45, thereby to provide a tensioning drive.

Also, during the normal slitting operation the diverting shafts 33 and 29 are retracted as shown in FIGURE 3 in phantom whereby these shafts clear the line of material 67 passing through the apparatus.

It will be further understood that the position of the diverting shaft 33 as shown in FIGURE 3 is representative of one particular position only and that the shaft 33 may be positioned more or less away from the curling shaft 22 as required to provide the desired curl 46. It will also be understood that the surface of the curling shaft 22 may be knurled to provide a more positive gripping action on the discard ends in order to ensure tension between curling shaft 22 and the pressure shafts 15 and 16.

It will be still further understood that although specific embodiments of the invention have been described and illustrated, the invention also contemplates such variations as may fall within the scope of the appended claims.

What I claim is:

1. Apparatus for maintaining tension in a high speed slitting line, and including curling means having an operative position and an inoperative position for curling starting ends of the sheet material being slit and comprising: a pair of pressure shafts resiliently biased together and horizontally positioned to pass said sheet material therebetween; a DC. motor drive, including electrical speed control therefor, and operatively connected to at least one of said pressure shafts, thereby to drive same to feed said sheet material therebetween and maintain tension in said line; a curling shaft rotatably supported in spaced apart parallel relationship with said pressure shafts adjacent the output side thereof; drive means operatively connected to said curling shaft; means for supporting said sheet material between said pressure shafts and said curling shaft and including a first diverting shaft, said first diverting shaft being movable from an operative position to an in- Operative position; and a second diverting shaft rotatably supported on adjustment means to have an operative position toward said curling shaft, whereby said material is forced into intimate contact with said curling shaft, and an inoperative position away from said curling shaft to clear said material coming from said pressure shafts.

2. Apparatus for maintaining tension in a high speed slitting line, and including curling means having an operative position and an inoperative position for curling starting ends of the sheet material being slit and comprising: a pair of pressure shafts resiliently biased together and horizontally positioned to pass said sheet material therebetween; a DC. motor drive, including electrical speed control therefor, and operatively connected to at least one of said pressure shafts, thereby to drive same to feed said sheet material therebetween and maintain tension in said line; a curling shaft rotatably supported in spaced apart parallel relationship with said pressure shafts adjacent the output side thereof; drive means operatively connected to said curling shaft; means for supporting said sheet material between said pressure shafts and said curling shaft and including a first diverting shaft, said first diverting shaft being movable from an operative position to an inoperative position; a second diverting shaft rotatably supported on adjustment means to have an operative position toward said curling shaft, whereby said material is forced into intimate contact with said curling shaft, and an inoperative position away from said curling shaft to clear said material coming from said pressure shafts; and means for selectively severing said sheet material at the input side of said pressure shafts.

3. Apparatus for maintaining tension in a high speed slitting line, and including curling means having an operative position and an inoperative position for curling starting ends of sheet material being slit and comprising: a pair of pressure shafts resiliently biased together and horizontally positioned to pass said sheet material therebetween; a DC. motor drive, including electrical speed control therefor, and operatively connected to at least one of said pressure shafts, thereby to drive same to feed said sheet material therebetween and maintain tension in said line; a curling shaft rotatably supported in spaced apart parallel relationship with said pressure shafts adjacent the output side thereof; drive means operatively connected to said curling shaft; means for supporting said sheet material between said pressure shafts and said curling shaft and including a first diverting shaft, said first diverting shaft being movable from an operative position to an inoperative position; a second diverting shaft rotatably supported on adjustment means to have an operative position toward said curling shaft, whereby said material is forced into intimate contact with said curling shaft, and an inoperative position away from said curling shaft to clear said material coming from said pressure shafts; a tilt arm pivotally supported below said curling shaft thereby adapted to receive said curled material therein; means for moving and supporting said tilt arm from a receiving position to a dumping position; and means for selectively severing said sheet material at the input side of said pressure shafts.

4. Apparatus for maintaining tension in a high speed slitting line, and including curling means having an operative position and an inoperative position for curling starting ends of the sheet material being slit and comprising: a pair of pressure shafts resiliently biased together and horizontally positioned to pass said sheet material therebetween; a DC. motor drive operatively connected to at least one of said pressure shafts, thereby to frictionally feed said sheet material therebetween; a voltage control for said DC. motor drive, whereby the speed thereof can be varied, thus to maintain tension on said sheet material at the input end of said apparatus, thereby to aid in maintaining tension in said slitting line; a curling shaft rotatably supported in spaced apart parallel relationship with said pressure shafts adjacent the output side thereof; drive 6 means operatively connected to said curling shaft; means for supporting said sheet material between said pressure shafts and said curling shaft and including a first diverting shaft, said first diverting shaft being movable from an operative position to an inoperative position; a second diverting shaft rotatably supported on adjustment means to have an operative position toward said curling shaft, whereby said material is forced into intimate contact with said curling shaft, and an inoperative position away from said curling shaft to clear said material coming from said pressure shafts; a tilt arm pivotally supported below said curling shaft thereby adapted to receive said curled material therein; means for moving and supporting said tilt arm from a receiving position to a dumping position; and means for selectively severing said sheet material at the input side of said pressure shafts.

5. Apparatus for maintaining tension in a high speed slitting line, and including curling means having an operative position and an inoperative position for curling starting ends of the sheet material being slit and comprising: a pair of pressure shafts resiliently biased together and horizontally positioned to pass said sheet material therebetween; a DC. motor drive operatively connected to at least one of said pressure shafts, thereby to frictionally Lfeed said sheet material therebetween; a voltage control for said DC motor drive, whereby the speed thereof can be varied, thus to maintain tension on said sheet material at the input end of said apparatus, thereby to aid in maintaining tension in said slitting line; a curling shaft rotatably supported in spaced apart parallel relationship with said pressure shafts adjacent the output side thereof; an AC. motor drive operatively connected to said curling shaft thereby to forcefully drive said material in tension to provide a curl therein; means for supporting said sheet material between said pressure shafts and said curling shaft and including a first diverting shaft, said first diverting shaft being movable from an operative position to an inoperative position; a second diverting shaft rotatably supported on adjustment means to have an operative position toward said curling shaft, whereby said material is forced into intimate contact with said curling shaft, and an inoperative position away from said curling shaft to clear said material coming from said pressure shafts; and means for selectively severing said sheet material at the input side of said pressure shafts.

6. Apparatus for maintaining tension in a high speed slitting line, and including curling means having an operative position and an inoperative position for curling starting ends of the sheet material being slit and comprising: a pair of pressure shafts resiliently biased together and horizontally positioned to pass said sheet material therebetween; a DC motor drive operatively connected to at least one of said pressure shafts, thereby to frictionally feed said sheet material therebetween; a voltage control for said DC motor drive, whereby the speed thereof can be varied, thus to maintain tension on said sheet material at the input end of said apparatus, thereby to aid in maintaining tension in said slitting line; a curling shaft rotatably supported in spaced apart parallel relationship with said pressure shafts adjacent the output side thereof; drive means operatively connected to said curling shaft; a guide table supported between said pair of pressure shafts and said curling shaft, the plane of said table extending substantially from the contact line of said pair of pressure rollers to a position tangential to said curling shaft; a first diverting shaft rotatably supported on vertical adjustment means, to have an operative position adjacent to said table, whereby said material from said pressure shafts is guided between said first diverting shaft and said table, and an inoperative position upwardly away from said table to clear said material coming from said pressure shafts; a second diverting shaft rotatably supported on vertical adjustment means to have an operative position toward said'curling shaft, whereby said material is forced into intimate contact with said curling shaft, and an inoperative position away from said curling shaft to clear said material coming from said pressure shafts; a tilt arm pivotally supported below said curling shaft thereby adapted to receive said curled material therein; means for moving and supporting said tilt arm from a receiving position to a dumping position; and means for selectively severing said sheet material at the input side of said pressure shafts.

7. Apparatus for maintaining tension in a high speed slitting line, and including curling means having an operative position and an inoperative position for curling startv ing ends of the sheet material being slit and comprising: a pair of pressure shafts resiliently biased together and horizontally positioned to pass said sheet material therebetween; a DC motor drive operatively connected to at least one of said pressure shafts, thereby to frictionally feed said sheet material therebetween; a voltage control for said DC motor drive, whereby the speed thereof can be varied, thus to maintain tension on said sheet material at the input end of said apparatus, thereby to aid in maintaining tension in said slitting line; a curling shaft rotatably supported in spaced apart parallel relationship with said pressure shafts adjacent the output side thereof; drive means operatively connected to said curling shaft; a guide table supported between said pair of pressure shafts and said curling shaft, the plane of said table extending substantially from the contact line of said pair of pressure rollers to a position tangential to said curling shaft; a first diverting shaft rotatably supported on vertical adjustment means, to have an operative position adjacent to said table, whereby said material from said pressure shafts is guided between said first diverting shaft and said table, and an inoperative position upwardly away from said table to clear said material coming from said pressure shafts; a second diverting shaft rotatably supported on vertical adjustment means to have an operative position toward said curling shaft, whereby said material is forced into intimate contact with said curling shaft, and an inoperative position away from said curling shaft to clear said material coming from said pressure shafts; adjustable means for determining the relative distance between said second diverting shaft and said curling shaft, thereby to determine the curl imparted to said sheet material during said operative condition; a tilt arm pivotally supported below said curling shaft thereby adapted to receive said curled material therein; means for moving and supporting said tilt arm from a receiving position to a dumping position; and means for selectively severing said sheet material at the input side of said pressure shafts.

8. Apparatus for maintaining tension in a high speed slitting line, and including curling means having an operative position and an inoperative position for curling starting ends of the sheet material being slit and comprising: a pair of pressure shafts resiliently biased together and horizontally positioned to pass said sheet material therebetween; a DC motor drive operatively connected to .at least one of said pressure shafts, thereby to frictionally feed said sheet material therebetween; a voltage control for said DC motor drive, whereby the speed thereof can be varied, thus to maintain tension on said sheet material at the input end of said apparatus, thereby to aid in maintaining tension in said slitting line; a curling shaft rotatably supported in spaced apart parallel relationship with said pressure shafts adjacent the output side thereof; an AC motor drive operatively connected to said curling shaft thereby to forcefully drive said material in tension to provide a curl therein; a knurled surface on said curling shaft thereby to increase the frictional contact with said sheet material; a guide table supported between said pair of pressure shafts and said curling shaft, the plane of said table extending substantially from the contact line of said pair of pressure rollers to a position tangential to said curling shaft; a first diverting shaft rotatably supported on vertical adjustment means, to have an operative position adjacent to said table, whereby said material from said pressure shafts 'is guided between said first diverting shaft and said table,

and an inoperative position upwardly away from said table to clear said material coming from said pressure shafts; a second diverting shaft rotatably supported on vertical adjustment means to have an operative position toward said curling shaft whereby said material is forced into intimate contact with said curling shaft, and an inoperative position away from said curling shaft to clear said material coming from said pressure shafts; adjustable means for determining relative distance between said second diverting shaft and said curling shaft, thereby to determine the curl imparted to said sheet material during said operative condition; a tilt arm pivotally supported below said curling shaft thereby adapted to receive said curled material therein; means for moving and supporting said tilt arm from a receiving position to a dumping position; and means for selectively severing said sheet material at the input side of said pressure shafts.

9. Apparatus for maintaining tension in a high speed slitting line, and including curling means having an operative position and an inoperative position for curling starting ends of the sheet material being slit and comprising: a pair of pressure shafts resiliently biased together and horizontally positioned to pass said sheet material therebetween; a DC motor drive operatively connected to at least one said pressure shafts, thereby to frictionally feed said sheet material therebetween; a voltage control for said DC motor drive, whereby the speed thereof can be varied, thus to maintain tension on said sheet material at the input end of said apparatus, thereby to aid in maintaining tension in said slitting line; scraper means located on at least one of said pressure shafts, thereby to clean same during operation; a curling shaft rotatably supported in spaced apart parallel relationship with said pressure shafts adjacent the output side thereof; an AC motor drive operatively connected to said curling shaft thereby to forcefully drive said material in tension to provide a curl therein; a knurled surface on said curling shaft thereby to increase the frictional contact with said sheet material; a guide table supported between said pair of pressure shafts and said curling shaft, the plane of said table extending substantially from the contact line of said pair of pressure rollers to a position tangential to said curling shaft; a first diverting shaft rotatably supported on vertical adjustment means, to have an operative position adjacent to said table, whereby said material from said pressure shafts is guided between said first diverting shaft and said table, and an inoperative position upwardly away from said table to clear said material coming from said pressure shafts; a second diverting shaft rotatably supported on vertical adjustment means to have an operative position toward said curling shaft, whereby said material is forced into intimate contact with said said curling shaft, and an inoperative position away from said curling shaft to clear said material coming from said pressure shafts; adjustable means for determining relative distance between said second diverting shaft and said curling shaft, thereby to determine the curl imparted to said sheet material during said operative condition; a tilt arm pivotally supported below said curling shaft thereby adapted to receive said curled material therein; means for moving and supporting said tilt arm from a receiving position to a dumping position; and means for selectively severing said sheet material at the input side of said pressure shafts.

10. In a coiling machine for strip material, the apparatus which comprises:

means for moving said strip material through said machine;

means for deflecting said strip material from a straight line path through said machine, said means comprising two unpowered shafts individually moveable into operative positions adapted to cause de- 3,836,77 7 9 10 flection of said strip material from said straight line References Cited path and into inoperative positions adapted not to UNITED STATES PATENTS cause deflection of said strip material from said straight line path; 1,850,312 3/1932 Biggert et al. 24278.2 a powered curling shaft positioned so as to not contact 5 1871665 8/1932 Dallas 242 78'2 said strip material when said strip material passes 2939645 6/1960 Rowlands et 242*782 through said machine in a straight line path, but to contact and curl said strip material when said un- RICHARD HERBST Primary Exammer' powered shafts are in said operative positions. MERVIN STEIN, Examiner. 11. Apparatus as claimed in claim 10, in which one 10 A E said unpowered shaft forms a nip with said curling shaft MINTZ xammer' when in operative position. 

1. APPARATUS FOR MAINTAINING TENSION IN HIGH SPEED SLITTING LINE, AND INCLUDING CURLING MEANS HAVING AN OPERATIVE POSITION AND AN INOPERATIVE POSITION FOR CURLING STARTING ENDS OF THE SHEET MATERIAL BEING SLIT AND COMPRISING: A PAIR OF PRESSURE SHAFTS RESILIENTLY BIASED TOGETHER AND HORIZONTALLY POSITIONED TO PASS SAID SHEET MATERIAL THEREBETWEEN; A D.C. MOTOR DRIVE, INCLUDING ELECTRICAL SPEED CONTROL THEREFOR, AND OPERATIVELY CONNECTED TO AT LEAST ONE OF SAID PRESSURE SHAFTS, THEREBY TO DRIVE SAME TO FEED SAID SHEET MATERIAL THEREBETWEEN AND MAINTAIN TENSION IN SAID LINE; A CURLING SHAFT ROTATABLY SUPPORTED IN SPACED APART PARALLEL RELATIONSHIP WITH SAID PRESSURE SHAFTS ADJACENT THE OUTPUT SIDE THEREOF; DRIVE MEANS OPERATIVELY CONNECTED TO SAID CURLING SHAFT; MEANS FOR SUPPORTING SAID SHEET MATERIAL BETWEEN SAID PRESSURE SHAFTS AND SAID CURLING SHAFT AND INCLUDING A FIRST DIVERTING SHAFT, SAID FIRST DIVERTING SHAFT BEING MOVABLE FROM AN OPERATIVE POSITION TO AN INOPERATIVE POSITION; AND A SECOND DIVERTING SHAFT ROTATABLY SUPPORTED ON ADJUSTMENT MEANS TO HAVE AN OPERATIVE POSITION TOWARD SAID CURLING SHAFT, WHEREBY SAID MATERIAL IS FORCED INTO INTIMATE CONTACT WITH SAID CURLING SHAFT, AND AN INOPERATIVE POSITION AWAY FROM SAID CURLING SHAFT TO CLEAR SAID MATERIAL COMING FROM SAID PRESSURE SHAFTS. 